Empty a GridView

以前，我被建议通过将其DataSource设置为null并调用DataBind()来清除GridView。然而，当我这样做时，我得到一个异常:

Specified argument was out of the range of valid values. Parameter name: index 

这个异常并不难诊断。问题是，当DataSource为空时，我如何清除我的GridView ?

编辑:下面是填充GridView的完整函数:

void PopulateGridView()
    {
        //Connect to database and get frames for selected job
        var dt = new DataTable();
        try
        {
            _connectionToDatabase.Open(); //open database
            var findDataCommand = new SqlCommand(SkidListSpName, _connectionToDatabase) { CommandType = CommandType.StoredProcedure };
            findDataCommand.Parameters.Add(new SqlParameter(SlParameter1, JobRelPhase_DropDown.SelectedValue));
            findDataCommand.Parameters.Add(new SqlParameter(SlParameter2, _stationId));
            var dataAdapter = new SqlDataAdapter(findDataCommand);
            dataAdapter.Fill(dt);
            if (dt.Rows.Count > 0)
            {
                gridView.DataSource = dt;
                gridView.DataBind();
            }
            else
            {
                gridView.DataSource = null; //HERE is where I set the DataSource
                gridView.DataBind(); //removing this removes the exception
                StatusLabel.Text = "No items found.";
            }
            _connectionToDatabase.Close(); //close database
        }
        catch (Exception e)
        {
            StatusLabel.Text = "No items found.";
            TestLabel.Text = e.Message;
        }
        finally
        {
            _connectionToDatabase.Close(); //close database
        }
    }